OBJECTIVES: To evaluate the trends and changes in the print summary formats of direct-to-consumer prescription drug advertisements (DTCA) in consumer magazines. METHODS: Print advertisements appearing in the National Geographic magazine from the period January 2000 to October 2003 were analyzed in this study. Data on advertisement formats, drugs advertised, and manufacturers were collected, coded, and analyzed. National Geographic magazine was selected because of its worldwide readership and appeal. RESULTS: A total of 128 advertisements were identified. The print DTCA advertised included 16 drug products by 9 manufacturers and two different types of print summary formats. The manufacturers accounting for most of the ads were Pfizer (28.91%) followed by GlaxoSmithKline (21.88%), Merck (15.63%) and Aventis (14.84%). Results of the analysis showed that less than half (43.75%) of the print DTCAs appearing in National Geographic were of the new easy to understand format. However, only four drugs were advertised with the new summary format, namely Avandia (15.63%), Viagra (14.06%), Vioxx (12.50%) and Singulair (1.56%). Trend analysis showed that in the year 2000, the percentage of print ads with the new format was 54%, which dropped to 40% in 2001. In 2002, it further dropped to 36%, but has risen to 47% in the year 2003. CONCLUSIONS: Companies that have adopted the new format have not done so universally for all their products. These new print DTCA summaries by being user friendly may induce positive attitudes toward the product, thus leading consumers to request more information regarding such drugs from physicians and pharmacists. Further studies are needed to evaluate consumer comprehension with the new summary format in print DTCA.